Add Sunsetter R2 by Charue Designs

[leeandher]

This PR adds Sunsetter R2 definition. I had downloaded it from the Charue Design discord before it shut down, and I'm not sure if the designer will add the definition themselves.

I don't have the keyboard on me to test at the moment, but I'll work with a friend to get screenshots and verify it.

QMK Pull Request

qmk/qmk_firmware#17269

Checklist

• The VIA support for this keyboard is MERGED in QMK master already (MANDATORY)
• The VIA definition follows the guide here: https://caniusevia.com/docs/layouts
• I have a V3 JSON version for this keyboard definition.(MANDATORY)
• I have tested this keyboard definition using VIA's "Design" tab.
• I have tested this keyboard definition with firmware on a device.
• I have assigned alpha keys and modifier keys with the correct colors.
• The Vendor ID is not 0xFEED

[leeandher]

Got the board from a friend, seemed to work as expected. Flashed with the firmware from https://www.caniusevia.com/docs/download_firmware and made sure I wasn't on V2 definitions.